Kola Superdeep Borehole

The Kola borehole ( Кольская сверхглубокая скважина; Kol'skaja swerchglubokaja skwaschina ) is a 1970 to 1989 carried out for scientific purposes geological drilling on the Russian Kola Peninsula.
She is since 1979 the deepest hole in the world, and had by 2008 also the longest hole.

The Kola Peninsula was chosen because here geologically very old rock formations are ( up to 2.5 billion years).
The hole is located about 10 km southwest of Sapoljarny.

Course

Preparations began in 1967. On May 24, 1970, began with the bore using the drilling rig used for conventional oil drilling Uralmash -4E.
In 1975 this was reduced to 1976 and replaced by the specially developed Uralmash -15000, which was designed for a depth of 15,000 m.
On June 6, 1979 9584 meters have been achieved, one meter more than the previous depth record of the bore Bertha Rogers in Oklahoma, USA.
On 27 December 1983, the well reached a depth of 12,000 meters.
By reaching this depth, the drilling activity was interrupted for a year.
1984 31 international scholars were invited to look at the project site.

Overall, created by the main vertical shaft several branching holes.
1989 the well was drilled SG -3 to a depth of 12,262 meters.
The hole had to be stopped at this depth because there unexpectedly high temperatures of 180 ° C instead of the expected 100 ° C were found.
The Kola borehole was drilled exceeded in length only in 2008 by a deep hole in the Al- Shaheen oil field in Qatar.
However, this hole only reached a depth of 1500 meters below the seabed, as the majority of this drilling ( 10,902 meters) went into the horizontal.

The rig was demolished in the summer of 2009.
Most of the more than 45,000 stored rock samples have not yet been investigated.

Legends

1989 came rumors of strange occurrences in the course of drilling into circulation.
The result was a legend that hell had been drilled, as you have heard voices from the deep.
This legend was widely disseminated and circulating until today.